JPH0367309B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a zinc bromine battery, and more particularly to a liquid circulation type zinc bromine secondary battery comprising a bromine removal device and a cell main body.

Zinc-bromine batteries have been studied for practical use in recent years because of their high energy density. For example, the first
The figure shows the basic configuration of an electrolyte circulation type zinc-bromine secondary battery.
is a cathode chamber, 4 is a diaphragm (separator), 5 is an anode, 6
is a cathode, 7 is an anolyte, 8 is a catholyte, 9 is an anolyte storage tank, 10 is a catholyte storage tank, and 11 and 12 are pumps. Conventionally, in these zinc-bromine batteries, the current efficiency (discharged capacity/charged capacity x 100%)
It was hoped that improvements would be made.

In general, the voltage efficiency (discharge voltage/
In order to improve the charge voltage x 100%, the distance between the anode and cathode 5 and 6 must be shortened to reduce voltage loss, or the electrolyte used must contain an additive (supporting electrolyte) that improves conductivity. The voltage efficiency can be maintained at such a high efficiency that it does not normally pose a problem by adding a liquid or the like. However, the energy efficiency of a zinc-bromine battery is expressed as the product of the above-mentioned current efficiency and voltage efficiency, so no matter how high the voltage efficiency is,
If the current efficiency is low, the energy efficiency will eventually deteriorate, so improving the low current efficiency of zinc-bromine batteries has been a conventional problem.

Factors related to improving the current efficiency of conventional zinc-bromine batteries include the composition of the diaphragm, electrodes, and electrolyte, the distance between the diaphragm and the electrode, current density, charging depth, and the like. First, the function of the diaphragm is to prevent bromine generated in the anode chamber during charging from diffusing into the cathode chamber of the counter electrode, and an ion exchange membrane or a porous membrane is used as the diaphragm. The ion exchange membrane considerably suppresses the diffusion of bromine (Br ₂ ) generated at the anode, and suppresses self-discharge with the zinc deposited on the cathode, giving the battery a high current efficiency of 90 to 99%. However, the high membrane electrical resistance in the electrolyte reduces voltage efficiency. On the other hand, porous membranes have a lower membrane electrical resistance than ion exchange membranes and less decrease in voltage efficiency, but cannot suppress the aforementioned bromine (Br ₂ ) diffusion as well as ion exchange membranes, and current efficiency is 70%.
~85%.

In addition, in order to reduce this self-diffusion and improve current efficiency, a method of increasing the thickness of the diaphragm is sometimes adopted, but this conversely increases membrane resistance (for example, electrical resistance and permeation resistance of zinc ions). However, it is not preferred because it has the disadvantage of lowering voltage efficiency.

Further, as for electrodes, the higher the discharge level, especially on the anode side, the better the current efficiency, so it is necessary to make special arrangements for the electrode in order to improve the discharge level, which is not economically advantageous.

Various additives have been proposed for the composition of the electrolytic solution, and although each has been effective to some extent, the composition changes depending on various conditions, and this problem has not yet been completely solved.

Factors other than those mentioned above, such as the distance between the diaphragm and the electrode, current density, and depth of charge, are determined not only by improving current efficiency, but also from the viewpoint of the overall energy density of the zinc-bromine battery. This is a matter of consideration, and is generally a factor that is not easily determined because it is only for improving current efficiency. In this way, zinc-
It has long been desired that other methods be used to improve the current efficiency of bromine batteries.

In order to prevent the current efficiency from decreasing due to the diffusion of bromine generated on the anode into the cathode chamber,
In a zinc-bromine secondary battery using a porous membrane with relatively high voltage efficiency as a diaphragm, the permeability is lower than that of an ion exchange membrane when the catholyte pressure in the cathode chamber and the anolyte liquid pressure in the anode chamber are varied. As a result of an experimental study on the relationship between the amount of electrolyte transfer through a large porous membrane and current efficiency, it was found that there was a large significant difference between them. In other words, in a zinc-bromine secondary battery in which the anode chamber and the cathode chamber are separated by a particularly porous membrane as a diaphragm, and the anolyte in the anode chamber and the catholyte in the cathode chamber are circulated, the catholyte pressure in the cathode chamber is controlled by the pressure in the anode chamber. The present invention is to increase the pressure of the anolyte to be higher than that of the anolyte, move the catholyte into the anode chamber through a porous membrane, diffuse bromine generated on the anode through the diaphragm onto the cathode, and prevent self-discharge with zinc on the cathode. I did it. Attached FIG. 2 is a diagram showing an embodiment of the above invention.
In addition, as a means for moving the catholyte, we have proposed a method of varying the amount of circulation by creating a difference in piping resistance loss in the circulation path or by differentiating the output of each circulation pump 11 and 12, as shown in Figure 2. It has been experimentally demonstrated that this significantly improves current efficiency compared to the case without liquid movement. However, in this method, the anolyte 7 in the anolyte storage tank 9 that has increased during charge/discharge cycle operation, especially the anolyte 7 with a low bromine content at the beginning of charge or the end of discharge, or the supernatant liquid of the anolyte is transferred to the catholyte storage tank 10. During charging and discharging or when stopped after charging and discharging, it is necessary to return the anolyte through the valve 18 of the common pipe connecting the anolyte storage tank 9 and the catholyte storage tank 10, resulting in the problem that bromine in the anolyte moves into the catholyte. be.

The object of the present invention is to further improve and stabilize the current efficiency of zinc-bromine batteries.

The gist of the present invention is to separate an anode chamber and a cathode chamber by a diaphragm, particularly a porous membrane, circulate the anolyte in the anode chamber and the catholyte in the cathode chamber through an anolyte storage tank and a catholyte storage tank, respectively, and In a zinc-bromine battery configured such that the catholyte pressure is greater than the anolyte pressure in the anode chamber and the catholyte is moved into the anode chamber through a porous membrane, a bromine removal device is provided between the anolyte storage tank and the catholyte storage tank. The electrolyte that has moved into the anode chamber is introduced into the bromine removal device to reduce the bromine concentration in the electrolyte, and the debrominated electrolyte is returned to the catholyte storage tank to prevent self-discharge with zinc on the cathode. Accordingly, it is an object of the present invention to provide a zinc-bromine secondary battery with improved current efficiency.

Furthermore, the present invention is a bromine removal device for reducing bromine concentration, characterized in that (1) a zinc-bromine electrolytic cell is formed; (2) a porous membrane, sulfonation, etc. are used as a pump and a diaphragm to improve ion exchange properties; It is characterized by a structure in which the electrolyte is passed through using a porous membrane and an ion exchange membrane.(3) Obtaining a low bromine concentration electrolyte that allows the synthesis of bromine complexes by passing the additive that complexes bromine through the solution. It is characterized by

This is a zinc-bromine battery using

The present invention will be further described in detail below based on the accompanying drawings.

3 to 8 are schematic diagrams showing embodiments of a zinc-bromine battery equipped with a bromine removal device.

FIG. 3 is a schematic diagram for explaining a bromine removal device featuring a zinc-bromine electrolytic structure, and FIG. - Schematic diagram showing the basic configuration of a bromine secondary battery.

FIG. 5 is a schematic diagram showing the basic configuration of a zinc-bromine secondary battery equipped with a bromine removal device characterized by using a diaphragm such as a porous membrane to obtain an electrolytic solution with a low bromine concentration. FIG. 6 is a schematic diagram showing a bromine removal apparatus different from the embodiment shown in FIG. 5. Figure 7 shows the basic configuration of a zinc-bromine secondary battery equipped with a bromine removal device that removes bromine as a bromine complex by passing an electrolytic solution through an additive solution that complexes bromine. FIG. 8 is a diagram showing another embodiment of the bromine removal apparatus shown in FIG. 7.

The same reference numerals in the above drawings indicate the same functions.

In Fig. 2, a pressure difference is created between the anode chamber 2 and the cathode chamber 3 inside the unit cell 1, and when the pressure inside the cathode chamber is higher than that of the anode chamber, the pressure inside the cathode chamber 3 is increased through the diaphragm 4 made of a porous membrane. The catholyte 8 is in the anode chamber 2
Therefore, the diffusion of bromine (Br ₂ ) in the anolyte 7 into the cathode chamber 3 is suppressed, self-discharge is suppressed, and the current efficiency can be significantly improved compared to a state where no pressure difference is applied. It is something.

The pressure difference that causes the movement of the catholyte is the first
is the catholyte 8 circulation system (cathode chamber 3 → outlet piping 1
4 → catholyte storage tank 10 → artificial piping 16 → pump 12
→The piping resistance loss from the outlet piping 14 to the inlet piping 16 of the cathode chamber 3) is calculated from the circulation system path of the anolyte 7 (anode chamber 2 → outlet piping 13 → anolyte storage tank 9 → inlet piping 15)
→ Pump 11 → Anode chamber 2) This is a method of making the pipe resistance loss larger than the pipe resistance loss from the outlet pipe 13 to the inlet pipe 15. Specifically, the cross-sectional area or length of the pipes 14 and 16 is The area or length may be made smaller or longer, or a valve 17 may be provided in the cathode chamber outlet piping 14 to increase the liquid pressure within the cathode chamber.

Next, the second method is to make the circulation amount of the catholyte 8 larger than the circulation amount of the anolyte 7, and for that purpose, the output of the catholyte pump 12 is increased from the output of the anolyte pump 12.
1 output.

As described above, by pressurizing the catholyte 8 in the cathode chamber 3, the catholyte is moved into the anode chamber 2.
When charging and discharging a bromine battery, the anolyte 7 in the anolyte storage tank 9 continues to increase because it is a mobile electrolyte. The increased liquid is gradually transferred to the catholyte storage tank using the valve 18 in the common piping between the anolyte storage tank and the catholyte storage tank, as an anolyte with a low bromine content or a supernatant liquid of the anolyte, especially at the beginning of charging or at the end of discharge. The electrolyte is returned to the catholyte reservoir 10 via the common piping by opening the valve 18 at full discharge, commonly referred to as a "wash", after the discharge. In this case, the former return method causes a smaller increase in current efficiency than the latter return method. In this method of increasing current efficiency by moving the electrolyte to the anode side using the pressure difference between the catholyte and the anolyte, it is necessary to return the electrolyte to the cathode side during or after charging and discharging, and eventually the electrolyte is transferred to the anode side. bromine migrates into the catholyte, causing problems such as interruption of operation.

Therefore, the inventor has developed an anolyte storage tank 9 and a catholyte storage tank 1.
A bromine removal device is installed between 0 and 0, and this removal device and zinc
This led to the invention of a zinc-bromine secondary battery that is connected to a bromine battery through a circulation conduit.

Figures 3 and 4 show the anolyte side, that is, the anolyte storage tank 9.
The electrolyte 7 transferred to the catholyte side, that is, the catholyte storage tank 1
This is an example in which a bromine removal device 21 is provided in the middle when returning to zero. The bromine removal apparatus 21 is an apparatus characterized by a zinc-bromine electrolytic structure having an anode 25 and a cathode 26, and an anode chamber 22 and a cathode chamber 23 separated by a diaphragm 24 made of a porous membrane. Zinc-bromine battery 1
The difference is that the catholyte 8 in the cathode chamber 23 is connected to the conduit 36.
is connected to the anolyte reservoir 9 by the other conduit 3
4 communicates with the catholyte storage tank 10. 19 is a charger/discharger, 39 is an auxiliary power supply device for the bromine removal device, and 46 is an insulating support portion between the anode 5 of the battery and the cathode 25 of the bromine removal device.

In a device having such a configuration, before charging and discharging the battery 1, a current is passed through the bromine removal device by the auxiliary power source 39 (in particular, it is preferable to use the battery during complete discharge, i.e., washing, after the battery main body is discharged) to remove zinc onto the cathode 26. Electrodeposit. On the other hand, bromine molecules generated on the anode 25 are diffused into the anolyte storage tank 9 through conduits 33 and 35. After zinc was electrodeposited on the cathode 26 of the bromine removal device 21 in this way, the battery 1 was charged twice using a method in which the pressure difference between the anode and cathode solutions was used to move the electrolyte to the anode side using the output difference between the pumps 11 and 12. When the discharger 19 is used in operation, the electrolyte that moves from the cathode chamber 3 in the battery 1 to the anode chamber 2 through the diaphragm 4 is introduced into the anolyte storage tank 9 via the conduit 13, and its water level rises to lower the water level in the catholyte storage tank 10. There is a difference between Due to the water level difference, the anolyte 7 flows into the cathode chamber 23 of the bromine removal device 21 via the conduit 36. Next, the bromine in the anolyte 7 that has flowed in and the zinc deposited on the cathode 26 cause self-discharge, and after passing through the cathode chamber 23, it becomes an electrolyte with a low bromine concentration and is introduced into the catholyte storage tank 10 through the conduit 34. be done. That is, when the electrolytic solution that has moved to the anode side due to the operation of the battery 1 is returned to the cathode side, the electrolytic solution with a low bromine concentration can be returned to the cathode side by the bromine removal device 21, thereby enabling operation with high current efficiency.

Instead of the auxiliary power source 39 for depositing zinc on the cathode 26 of the bromine remover 21, the bromine remover 21 may be powered from the terminals of the battery 1 by means of a changeover switch 47. In this case, if this is done when the battery is washed or completely discharged, the loss of the entire system will be reduced and the efficiency will be improved. Furthermore, if the bromine removal device 21 and the battery 1 are stacked as shown in FIG. 3, there is an advantage that the installation space is not taken up and the electrode area of the device can be increased.

Next, an embodiment of the second bromine removal device will be described based on FIGS. 5 and 6.

In FIG. 5, the zinc-bromine stacked battery 1 is connected to the anolyte storage tank 9 and the catholyte storage tank 10 through conduits 13 and 14, and the outlet side of the anolyte pump 11 is connected to the battery 1 side and the bromine removal device 21 through conduits, respectively. 15
and branched into a conduit 33, and a valve 2 is installed in the conduit 33.
8 will be provided. On the other hand, the bromine removal device 21 has a structure in which a liquid chamber 31 and a liquid chamber 32 are separated by a diaphragm 24, and a conduit 35 is connected to the other side of the liquid chamber 31.
The interior thereof is communicated with the anolyte storage tank 9 through a valve 27, and the liquid chamber 32 and the catholyte storage tank 10 are connected through a conduit 34.

In the apparatus having such a configuration, when returning the electrolyte that has moved to the anolyte storage tank 9 due to the operation of the battery 1 to the catholyte storage tank 10, the valves 27 and 28 are adjusted to close the liquid chamber 31. The liquid chamber 32 is passed through the diaphragm 24 while adjusting the pressure and inflow amount inside the liquid chamber 32.
Transfer the electrolyte to Since the diaphragm 24 is composed of a porous membrane, a porous membrane with ion exchange properties, an ion exchange membrane, etc., bromine in the electrolyte is passed through the diaphragm, and the electrolyte with a low bromine concentration is stored in the liquid chamber 32. A liquid is introduced and this electrolyte is returned to the catholyte reservoir 10 by conduit 34. As a result, the bromine concentration in the electrolyte can be suppressed and the electric current efficiency can be improved.

FIG. 6 shows an example in which the bromine removal device 21 described above has a plurality of diaphragms and a large number of liquid chambers, and instead of the valve 27, the valve 27 is throttled by a channel 37 consisting of a conduit having a smaller cross-sectional area than the conduit 35. This is an example of obtaining an electrolytic solution with a low bromine concentration by introducing it into each liquid chamber with the same liquid resistance as the bromine ratio. Furthermore, the valve 28 is closed without forcibly returning the increased anolyte by the pump 11, and the anolyte increased due to the difference in the level of the positive and negative fluid that occurs during charging and discharging is transferred from the conduit 35 to the channel 3.
There is an advantage that the flow can be returned by the flow of 7 → diaphragm 24 → conduit 34. The advantage of this bromine removal device is that it is structurally simple and does not require additional energy.

Next, an embodiment of an apparatus for synthesizing a bromine complex using a third bromine complexing additive and removing bromine to a low concentration will be described with reference to FIGS. 7 and 8.

In FIG. 7, the anode chamber 2 of the battery 1 is connected to the conductor 13,
15 connects the catholyte chamber 3 to the anolyte storage tank 9 via the pump 11, and similarly connects the cathode chamber 3 to the catholyte storage tank 10 via the pump 12 via conduits 14 and 16. The bromine removal device 21 includes an anolyte storage tank 9 and a conduit 33.
The catholyte storage tank 10 is connected to the catholyte storage tank 10 by a conduit 34 and a conduit 35 . Inside the bromine removal device 21, there is an additive 40 that reacts with bromine to synthesize a bromine complex, such as an amine compound (tripropylamine bromate, tributylamine bromate, etc.) 3.
and quaternary amine compounds (methyl, ethyl, morpholinium salts, methyl, ethyl, pyrrolidium salts,
methyl, decyl, pyrrolidium salts, etc.), and is separated from the anolyte 7 in the anolyte storage tank 9 by a diaphragm 44 in the conduit 35.

Next, the operation of the present bromine removal device 21 will be described. As in the embodiment described above, the electrolyte transferred to the anolyte storage tank 9 due to the operation of the battery 1 is transferred to the catholyte storage tank 1.
When returning to zero, due to the water level difference between the two storage tanks, the conduit 33
The electrolytic solution with a high bromine concentration in the anolyte storage tank 9 is introduced into the bromine removal device 21 through the anolyte storage tank 9, and when mixed with the additive, the bromine in the electrolytic solution is converted into a bromine complex compound by the additive. The electrolyte with the reduced bromine concentration is separated as a supernatant inside the bromine removal device and returned to the catholyte storage tank 10 through conduit 34. The bromine complex formed by reaction with bromine settles into the additive 40 and passes to the diaphragm 44 of the conduit 35. Through this diaphragm 44, bromine permeates and diffuses into the anolyte at a rate corresponding to the bromine concentration of the anolyte 7 in the anolyte storage tank 9. The liquid that has moved to the anode side inside the battery 1 in this way returns to the cathode side as an electrolyte with a low bromine concentration by the present bromine removal device 21, suppressing the bromine concentration in the electrolyte and increasing the current efficiency of the battery. It can be improved.

In addition, FIG. 8 shows that, depending on the type of additive, the generated bromine complex does not precipitate but floats, so a large porosity is placed above the additive liquid in the bromine removal device 21 at a position lower than the lower side of the pipe 34. This is an example using a diaphragm 45 made of a membrane, cloth, or the like.

Next, examples of the present invention will be described together with comparative examples in which a bromine removal device is not provided.

(1) Comparative example In the battery configuration shown in the attached Figure 2, a commercially available porous membrane with a thickness of 0.4 mm (manufactured by Asahi Kasei Corporation) was used as the diaphragm 4.
FP membrane) was used, and 0.5 mole of methyl, ethyl, morpholinium bromide as a complexing agent and 0.5 mole of methyl, ethyl, pyrrolidium bromide were added to 3 mole of zinc bromide solution as the electrolyte, and 1 mole of methyl, ethyl, and pyrrolidium bromide as a complexing agent. Furthermore, 0.2 mol/bromine was added to the anolyte.

Pumps 11 and 12 were DC motor pumps, and the input voltage and current were adjusted to adjust the pressure of each electrolytic solution.

Charging was carried out for 3 hours at a current density of 20 mA/cm ² , and discharging was carried out at a current density of 20 mA/cm ² until the battery voltage decreased to 1 volt.

Under the above conditions, the pump discharge pressure of both electrolytes was set to 0.1.
The current efficiency when operated at Kg/cm ² was 82%.

Next, the discharge pressure of the anolyte pump 11 was set to 0.1 Kg/cm ² and the discharge pressure of the catholyte pump 12 was set to 0.2 Kg/cm ² , and the electrolyte that had moved to the anolyte was returned by opening the valve 18 and connecting the catholyte and anolyte storage tanks.

The current efficiency in this case was 85%.

Example ¹ In the bromine removal apparatus 21 of the present invention shown in FIG.
No. 4 used an ion exchange membrane and was charged at 0.5 A and 1.8 V for 30 minutes to deposit zinc on the cathode 26.

Next, for battery operation, the discharge pressure of the anolyte pump 11 is
0.1Kg/cm ² and the discharge pressure of catholyte pump 12 is 0.2
Kg/cm ² , the charging and discharging conditions were the same as in the comparative example, and as a result of measuring the current efficiency, a high efficiency of 93% was obtained. In other words, this is an 8% improvement over the comparative example obtained by simply adding a hydraulic pressure difference.

Example 2 In the bromine removal device 21 of the present invention shown in FIG. 5, five porous membranes (FP membrane manufactured by Asahi Kasei Corporation) with a diaphragm 24 having an area of 100 cm ² and a thickness of 1.2 mm were assembled and piped to use the device. there was. The input voltages of the valves 27 and 28 and the anolyte pump 11 were adjusted so that the amount of liquid transferred from the cathode chamber to the anode chamber inside the battery and the amount of liquid returned to the catholyte storage tank 10 through the bromine removal device 21 were made to be similar.

The pump discharge pressure was the same as in Example 1, and the charging and discharging conditions of the battery were the same as in the comparative example, and the battery was operated and the current efficiency was measured, and as a result, 90% was obtained. 5% compared to comparative example
This shows an improvement in

Example 3 Using the apparatus of the present invention shown in Figure 7, methyl, decyl, and pyrrolidium salts, which are one type of quaternary amine, were added as additives The capacity of the bromine removal device was 300 ml, and 500 g of the above-mentioned additives were added to achieve a supersaturated state.

The battery was operated under the same conditions as the comparative example and the pump discharge pressure was the same as in Example 1. As a result, the current efficiency was 90.
I got %.

This result shows an improvement of 5% over the comparative example.

As is clear from the results of the above examples, it is clear that the zinc-bromine battery according to the present invention is a useful invention that can maintain a high current efficiency.

[Brief explanation of drawings]

Figure 1 is a schematic diagram showing the basic configuration of an electrolyte circulation type zinc-bromine secondary battery, Figure 2 is a modified schematic diagram of an electrolyte circulation type zinc-bromine secondary battery, and Figure 3 is an example. Figure 4 is a schematic diagram of the bromine removal equipment in Figure 3.
FIG. 5 is a schematic diagram showing the basic structure of a zinc-bromine secondary battery according to an embodiment of the present invention, which is equipped with the bromine removal device shown in the figure. A schematic diagram showing the basic configuration of a secondary battery, FIG. 6 is a schematic diagram of a bromine removal device different from the embodiment shown in FIG. FIG. 8 is a schematic diagram showing the basic configuration of a zinc-bromine secondary battery equipped with a bromine removing device, and FIG. 8 is a diagram showing another embodiment of the bromine removing device shown in FIG. 1: Zinc bromine battery, 2: Anode chamber, 3: Cathode chamber,
4: diaphragm, 5: anode, 6: cathode, 9: anolyte storage tank, 10: catholyte storage tank, 11, 12: pump, 1
8: common valve, 19: charger/discharger, 21: bromine removal device, 25: anode for bromine removal device, 26: cathode for bromine removal device, 27, 28: bulb, 31, 3
2: Liquid chamber, 39: Auxiliary power supply device, 40: Additive solution.

Claims (1)

[Scope of Claims] 1. The anode chamber and the cathode chamber are separated by a diaphragm, and the anolyte in the anode chamber and the catholyte in the cathode chamber are circulated through an anolyte storage tank and a catholyte storage tank, respectively, and the catholyte in the cathode chamber is circulated through an anolyte storage tank and a catholyte storage tank, respectively. In a zinc-bromine battery, the pressure is greater than the anolyte pressure in the anode chamber, and the catholyte is moved through the diaphragm into the anode chamber,
A zinc bromine battery characterized in that a bromine removal device 21 is provided between the anolyte storage tank 9 and the catholyte storage tank 10, and the electrolyte that has moved into the anode chamber is returned to the catholyte storage tank via the bromine removal device. 2. The zinc bromine battery according to claim 1, wherein the diaphragm is a porous membrane. 3 A bromine removal device comprising a zinc-bromine electrolytic cell comprising an anode and a cathode, with the anode chamber and cathode chamber separated by a diaphragm, and the cathode chamber of the bromine removal device is separated from an anolyte storage tank and a catholyte storage tank. 2. The zinc bromine battery according to claim 1, wherein the anode chamber is connected to the anolyte storage tank through a conduit. 4. The zinc bromine battery according to claim 3, characterized in that the bromine removal device and the battery components are stacked. 5 A bromine removal device consisting of a plurality of liquid chambers separated by a porous membrane, a porous membrane imparted with ion exchange properties, or a diaphragm made of an ion exchange membrane, wherein one end of the liquid chamber of the bromine removal device is characterized by comprising a conduit and a control valve for introducing the anolyte from the anolyte storage tank, and a conduit and a control valve that communicate with the anolyte storage tank, and the other end of the liquid chamber and the catholyte storage tank are connected by the conduit. Claim 1
Zinc bromine battery as described in section. 6. The liquid chamber of the bromine removal device and the anolyte storage tank are connected to each other by a conduit having a cross-sectional area smaller than that of the conduit. Zinc bromine battery. 7 A bromine removal device which includes a solution of additives such as tertiary and quaternary amine compounds that convert bromine in an electrolytic solution into a bromine complex, and an anolyte storage tank is placed in the solution of the bromine removal device. Claim 1, characterized in that a conduit for introducing the anolyte, a conduit communicating with the anolyte storage tank, and a diaphragm in the communication conduit, and communicating with the catholyte storage tank in the upper part of the bromine removal device. zinc bromine battery. 8. The zinc-bromine battery according to claim 7, wherein the additive that causes bromine to form a bromine complex is supersaturated.